Wetpaint is launching a whiteboard application for Facebook. Now you can collaborate on a whiteboard with friends--wiki style. The Wetpaint Facebook app isn't live yet, but will be available to all starting tomorrow. You'll also need to first join the Wetpaint group in order to access the Facebook application. There are a few starter whiteboards that Wetpaint has created, like "Class Notes" and "Party Planner." You can also launch a wiki for your a topic of your choosing. To get things started right, Wetpaint is holding a sweepstakes for all users of the Whiteboard Facebook app--get an 8GB iPhone (just don't add any third party software once you get it). Wetpaint's own website version of the whiteboard is the Please Touch feature, for group collaboration on artwork.